Gizmo5

Gizmo5 (formerly known as Gizmo Project and SIPphone) was a Voice over Internet Protocol communications network and a proprietary freeware soft phone for that network. On November 12, 2009, Google announced that it had acquired Gizmo5. On March 4, 2011, Google announced that the service would be discontinued as of April 3, 2011.

The Gizmo5 network used open standards for call management, Session Initiation Protocol (SIP) and Extensible Messaging and Presence Protocol (XMPP). However, the Gizmo5 client application was proprietary software and used several proprietary codecs, including GIPS and Internet Speech Audio Codec (iSAC).

Read more about Gizmo5:  History, Technology, Service Features, Mobile Phone Support, Gmail, Service Terminated